heres a lil step by step for you! :
1. click download now, you can donate to this lovely creator or click "take me to downloads"
2. click the one with "win" in the title
3. if your using google, the download button next to your profile icon should be blue and you can click that and then click the download which should bring you to your files
4. on the top bar click "extract all", a screen will pop up and you should just click "extract" and a progress bar will appear
5. once its finished, itll bring you to the folder which you open and then to open the game, you click the one with the icon and is the file type "application"
Hope this helps!
You cant pay on mobile